The present application claims priority upon Japanese Patent Application No. 2001-87233 filed on Mar. 26, 2001, which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to a storage area network system, a storage, and a data transfer amount monitoring apparatus.
2. Description of the Related Art
Recently, due to the complexity of system management and with the aim of reducing system operation management cost, there is rapid growth in services such as an Internet Data Center (hereinafter referred to as “IDC”) or a Storage Service Provider (hereinafter referred to as “SSP”). These services provide management of servers consigned by a corporation and central management of data thereof.
With the IDC and SSP, in particular, a Storage Area Network (hereinafter referred to as “SAN”) which uses a fiber channel capable of high-speed and long distance data transfer is connected with a plurality of servers and storages to construct the SAN system, thus storage management is integrated. This storage is constructed of a large scale disk array equipped with multiple large-capacity magnetic disks, and centrally manages large amounts of various data that are consigned. An end user, from his/her own information terminal (hereinafter referred to as “user terminal”), via such as a Wide-area Network (hereinafter referred to as “WAN”) and a Local Area Network (hereinafter referred to as “LAN”), accesses a user server inside the IDC and SSP. The user server responds to a request from the user terminal, and conducts transmittance of data by connecting to the storage via the SAN.
In such a SAN system, it is necessary to control the data transfer amount to be transmitted, in order to respond to data transfer requests which concentrate from the respective server. Conventionally, when the user terminal accesses the storage through the user server, a method of controlling the transmittable data transfer amount is used, and a connecting speed (line speed) for data transfer is limited by using such as a switching hub on the network which is connected to the server. In this case, an expensive switching hub must be introduced to the entrance of the network connecting to the WAN, and the cost becomes extremely high.
Then, the present applicant proposed a method/system of limiting the speed of data transfer between the server and the storage, without using an expensive switching hub. In other words, the ports of the plurality of fiber channels installed to the storage side are made to differ in data transfer speed from each other. These port groups deal with the various data transfer requested by the respective server. As a specific operation, in a contract with a service user, a prescribed data transfer amount is determined for respective servers, and the respective server selects a storage port appropriate for its own data transfer amount, and then performs data transfer.
However, there is a case where the server makes a request exceeding the prescribed data transfer amount determined in the contract. When such an unplanned request of data transfer exceeding predicted values is accepted, there occurs an obstruction in other data transfer, and the entire SAN system deteriorates in response performance in respect to requests from the respective servers.
As an example, when there is a data transfer request from a certain server, if it is in accordance with the contract, usually only a port with a line speed of 60 MB/S or less needs to be used. In the case a request for data transfer amount exceeding the provision occurs, since a conventional storage does not have a port which can control the transfer speed, the maximum transfer speed prepared on the storage side is to be used. Then, when a different server requests for a large-capacity data transfer, the port with the maximum speed which was originally usable can not be selected and used. Thus, a hindrance such as a delay in data transfer occurs, and a response performance of the entire SAN system deteriorates.